The debug system described in this patent specification provides a system that generates hardware elements from normally non-synthesizable code elements for placement on an FPGA device. This particular FPGA device is called a Behavior Processor. This Behavior Processor executes in hardware those code constructs that were previously executed in software. When some condition is satisfied (e.g., If . . . then . . . else loop) which requires some intervention by the workstation or the software model, the Behavior Processor works with an Xtrigger device to send a callback signal to the workstation for immediate response.